1. Field of the Invention
This invention relates to the insulative finishing of walls, and more particularly concerns a product to be applied to walls and a method for constructing a wall covering having a continuous cementitious outer layer.
2. Description of the Prior Art
A widely used method of exterior insulation and stucco wall construction involves fastening panels of expanded polystyrene insulation, generally measuring two foot by four foot by 3/4 inch, to the outer face of an exterior wall. A uniform layer of portland cement is typically trowelled upon the outer surface of the polystyrene panels, and a reinforcing fabric such as an open weave scrim of continuous filament fiberglass is embedded into the wet cement. Once the cement has hardened, a finish stucco coat is applied by trowel and "floated" to a desired texture.
The glass fiber reinforcing fabric is generally available in a 36 inch wide, 100 foot roll, and has a square weave construction providing a mesh size of approximately 1/4 inch. The fabric is typically cut to size from the roll by workers on scaffolding. Two workers are required to effectively unroll, cut and embed the fabric in the cement. Such work has inherent hazards due to sometimes windy conditions and unstable footing on scaffolding surfaces wet with cement. Additionally, sharp knives are needed to cut the fabric, and workers must stretch long spans while holding and controlling the draping of long sheets of cut fabric. The process is often time consuming due to the difficulty in embedding the fabric evenly, without buckles and folds, around various contours and overlapping adjacent polystyrene panels. Often the fabric must be pulled down, the cement smoothed, and the fabric reembedded. This is a costly process that generally requires two skilled laborers.
It would therefore be desirable to have construction products and methods which will achieve safer, faster, and qualitatively improved results in stucco wall construction without sacrificing structural strength.
Accordingly it is an object of the present invention to provide a thermally insulative panel product which affords improved anchoring of cementitious coatings employed in stucco wall construction.
It is another object of the present invention to provide a product of the aforesaid nature which will obviate the need for applying reinforcing fabric as a separate step in stucco wall construction.
It is yet another object of the invention to provide a product of the aforesaid nature which is stackable, simple to use, and amenable to low cost manufacture.
It is still another object of the present invention to provide a faster, and less hazardous method of construction of a stucco finish wall that may be accomplished by a single worker.
These objects and other objects and advantages of the invention will be apparent from the following description.